a pointer filled in with the number of keyboards returned, may be NULL.
a 0 terminated array of keyboards instance IDs or NULL on failure; call SDL_GetError() for more information. This should be freed with SDL_free() when it is no longer needed.
Threadsafety: This function should only be called on the main thread.
Get a list of currently connected keyboards.
Note that this will include any device or virtual driver that includes keyboard functionality, including some mice, KVM switches, motherboard power buttons, etc. You should wait for input from a device before you consider it actively in use.